Zaharescu Traian, Nicula Nicoleta, Râpă Maria, Iordoc Mihai, Tsakiris Violeta, Marinescu Virgil Emanuel
INCDIE ICPE CA, 3131 Splaiul Unirii, 030138 Bucharest, Romania.
Faculty of Materials Science and Engineering, University Politehnica of Bucharest, 313 Splaiul Independentei, 060042 Bucharest, Romania.
Polymers (Basel). 2023 Jan 30;15(3):696. doi: 10.3390/polym15030696.
Ultra-high-molecular-weight polyethylene (UHMWPE) matrices containing low-density polyethylene (LDPE), hydroxyapatite (HAp) as filler, and rosemary extract (RM) as stabilizer were investigated for their qualification for long-term applications. The significant contributions of the blend components were analyzed, and variations in mechanical properties, oxidation strength, thermal behavior, crystallinity, and wettability were discussed. SEM images of microstructural peculiarities completed the introspective survey. The stability improvement due to the presence of both additives was an increase in the total degradation period of 67% in comparison with an unmodified HDPE/UHMWPE blend when the materials were subjected to a 50 kGy γ-dose. There was growth in activation energies from 121 kJ mol to 139 kJ mol when HAp and rosemary extract delayed oxidation. The exposure of samples to the action of γ-rays was found to be a proper procedure for accomplishing accelerated oxidative degradation. The presence of rosemary extract and HAp powder significantly increased the thermal and oxidation resistances. The calculation of material lifetimes at various temperatures provided meaningful information on the wearability and integrity of the inspected composites.
研究了含有低密度聚乙烯（LDPE）、作为填料的羟基磷灰石（HAp）以及作为稳定剂的迷迭香提取物（RM）的超高分子量聚乙烯（UHMWPE）基体在长期应用中的适用性。分析了共混物各组分的重要作用，并讨论了其力学性能、氧化强度、热行为、结晶度和润湿性的变化。微观结构特性的扫描电子显微镜（SEM）图像完善了该深入研究。当材料受到50 kGy的γ剂量照射时，与未改性的HDPE/UHMWPE共混物相比，由于两种添加剂的存在而导致的稳定性提高是总降解期增加了67%。当HAp和迷迭香提取物延缓氧化时，活化能从121 kJ/mol增加到139 kJ/mol。发现将样品暴露于γ射线作用下是实现加速氧化降解的合适方法。迷迭香提取物和HAp粉末的存在显著提高了热稳定性和抗氧化性。计算不同温度下材料的寿命为所检测复合材料的耐磨性和完整性提供了有意义的信息。
